The invention relates to a process for the preparation of optically active phenyl-glycine amide by subjecting a mixture of L- and D-phenyl-glycine amide to optical resolution.
A mixture of L- and D-phenyl-glycine amide herein also denotes the racemate of phenyl-glycine amide and mixtures of the racemate with the L-isomer and/or D-isomer.
Phenyl-glycine amide can be hydrolyzed to phenyl-glycine in a simple way, e.g., by treatment with sulphuric acid, as described in Journal of the Chemical Society (1966) pages 393-397. Thus, the present process is of importance in the preparation of optically active phenyl-glycine. The prior art method for the production of optically active phenyl-glycine is a rather expensive method, in which D-phenyl-glycine is prepared by reaction of .alpha.-bromo-(D-camphor) sulphonic acid (see: Berichte 41, page 2073). This prior art method is very laborious and has the drawback that the rather expensive separating agent gets lost during the processing steps.